4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be...

19
Selection of our books indexed in the Book Citation Index in Web of Science™ Core Collection (BKCI) Interested in publishing with us? Contact [email protected] Numbers displayed above are based on latest data collected. For more information visit www.intechopen.com Open access books available Countries delivered to Contributors from top 500 universities International authors and editors Our authors are among the most cited scientists Downloads We are IntechOpen, the world’s leading publisher of Open Access books Built by scientists, for scientists 12.2% 122,000 135M TOP 1% 154 4,800

Transcript of 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be...

Page 1: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Selection of our books indexed in the Book Citation Index

in Web of Science™ Core Collection (BKCI)

Interested in publishing with us? Contact [email protected]

Numbers displayed above are based on latest data collected.

For more information visit www.intechopen.com

Open access books available

Countries delivered to Contributors from top 500 universities

International authors and editors

Our authors are among the

most cited scientists

Downloads

We are IntechOpen,the world’s leading publisher of

Open Access booksBuilt by scientists, for scientists

12.2%

122,000 135M

TOP 1%154

4,800

Page 2: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

9

Climate Signals from 10Be Records of Marine Sediments Surrounded with Nearby a Continent

Kyeong Ja Kim1 and Seung-Il Nam2 1Korea Institute of Geoscience and Mineral Resources

2Korea Polar Research Institute Korea

1. Introduction

Climate signals from 10Be records in marine environments have been studied for last two decades (Aldahan et al., 1997, Bourlès et al., 1989, Christl et al., 2003, Eisenhauer et al., 1994, Horiuchi et al., 2000, 2001, Kim and Nam, 2010, Knudsen et al., 2008, McHargue et al., 2010, McHargue and Donahue, 2005). Understanding of regional climate signals is feasible through not only 10Be but also 9Be from the sediment. This is because 9Be is terrigenous origin while 10Be signal is affected by climatic condition and production at the top of atmosphere. Recent study from the East Sea of Korea (05-GCRP-21) indicated that climate signals from 10Be records of Korean marine sediment are generally representing global climate variations during warm and cold periods from Last Glacial Maximum to Holocene and also MIS (marine isotope stage) 6 to Eemian. The 10Be records of the East Sea are well compared with those from the oxygen isotopic record of this marginal sea (Kim and Nam, 2010). During the warm interglacial periods the 10Be concentrations per sediment mass have significantly increased while during the cold glacial periods those have decreased (Aldahan et al., 1997, Eisenhauer et al., 1994). This result also shows that a vivid record of 10Be/9Be indicates a significant increase of 10Be at a time of 120 kyr, which might be an indication of the paleomagentic excursion. Interestingly, it was found that the 10Be concentrations per 1g sediment of this region were about 30% lower than other 10Be records of largely open marine environment. We also found that 10Be concentrations of the Blake Outer Ridge were similar to those from Korean marine sediments (McHargue et al., 2000). Two study areas are located nearby large continents: the East Asia (the East Sea) vs North America (the Atlantic). This could be caused by sediment inflow to the marine environment which is close enough to the continent. Therefore, local marine environmental influence is revealed through the beryllium isotopes. Both cases would have similar climatic signals due to their geographical locations nearby continent. The lower 10Be concentrations for these regions could be also involved in ocean current and circulation. Relatively deep sea water of these regions may not be well mixed rapidly with the surface water and old sea water with relatively lower 10Be concentration remains in the sediment records. For this chapter, we investigated climatic signals from Be isotope records of the East Sea of Korea and the Mendeleev Ridge of the Arctic Ocean and compared with the records from the Blake Outer Ridge studied by McHargue et al., 2000. In addition, global 10Be records of marine sediments for various regions will be briefly discussed. This chapter

www.intechopen.com

Page 3: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

180

would provide a new insight guide into understanding climate signals through 10Be records of various marine environments.

2. Beryllium isotopes in terrestrial environments

2.1 Cosmic ray induced 10Be production rate Production rates of cosmogenic isotopes depend on geomagnetic latitude, altitude, and flux of incoming cosmic rays to the earth (Lal, 1988). The Earth’s geomagnetic field deflects incoming cosmic rays and has an effect on the production rate of in situ cosmogenic isotopes. This deflection affects the incident angle and the rigidity of cosmic rays. The rigidity is defined as r = pc/q, where p is the momentum, q is the charge of the particle, and c is the velocity of light (O’Brien, 1979). The vertical cutoff rigidity is the lowest at the geomagnetic poles and highest at the equator. Therefore, greater cosmic rays reach to the poles and attenuation length at low latitude is greater than at high latitude (Simpson and Uretz, 1953). Since geomagnetic latitude affects the production rate of cosmogenic isotopes, understanding of the secular variation of the Earth’s geomagnetic field is important. It is known that variations of geomagnetic field intensity cause changes in the flux of cosmic rays, in solar activity, and in shielding by the Earth’s magnetosphere. Laj et al., 1996 describes geomagnetic intensity and 14C abundance in the atmosphere and ocean during the past 50 kyr. This paper shows geomagnetic change effects on the 14C production, which is increased by the decrease of the Earth’s dipole moment. Similarly, the relationship between 10Be production rate and geomagnetic field intensity was studied using deep-sea sediments. These results also demonstrate the importance of the relationship between cosmogenic nuclide production and intensity of geomagnetic dipole moment variation (Frank et al., 1997). Thus, production of cosmogenic isotope should be corrected with the variation of geomagnetic dipole moment variation. It has been found that the Earth’s geomagnetic pole is essentially the geographic pole for periods greater than about 2 kyr (Champion, 1980, Ohno and Hamano, 1992). Therefore, a correction from geographic reading to geomagnetic reading is required. For most cases of 10Be or 26Al surface exposure dating samples, the working range of age is from several thousand years to a few million years. Thus, in this case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic dipole moment intensity is required. Masarik et al., 2001 demonstrated the correction of in situ cosmogenic nuclide production rates for geomagnetic field intensity variations during the past 800 kyr. This paper indicated that at the equator integrated production rates for exposure ages between ~40 and 800 kyr are 10 to 12% higher than the present day value, whereas at latitudes greater than 40 degree, geomagnetic field intensity variations have hardly influenced in situ cosmogenic nuclide production. Production rates as a function of both latitude and altitude have been studied in the past.

For a few decades, models from Lal and Peters, 1967 and Lal, 1988, have been widely used

for the scaling factors for production rates of in situ produced cosmogenic nuclides. A

third degree polynomial equation found in Lal, 1991, enables one to calculate the

production rate of 10Be and 26Al with respect to geomagnetic latitude and altitude. A

reevaluation of scaling factors for these production rates has been attempted recently

using non-dipole contributions of the geomagnetic field to the cosmic ray flux and

observed attenuation lengths (Dunai, 2000). The scaling factors for the nuclear

disintegration with respect to geomagnetic latitude and altitude from Lal’s work are

www.intechopen.com

Page 4: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

181

involved in the geocentric axial dipole hypothesis and this is appropriate for time scales

exceeding 200 kyr. The non-dipole components of the Earth’s magnetic field contribute up

to 20% to the total field; therefore, they must be considered for short-term effects of

cosmic rays. It is known that the new scaling factors and those of Lal are significantly

different, by up to about 30%, especially at high altitude and at low latitude. Currently, a

few other research groups have been involved in studying production rates of cosmogenic

nuclide or measurement of neutron flux as a function of geomagnetic latitude and

altitude. This additional research on this field may provide a confirmation of these scaling

factors for the production of in situ cosmogenic isotopes. (Stone, 2000, Graham et al.,

2005a,b,c, 2000, Lifton et al., 2001, Desilets et al., 2006).

2.1.1 Production rate in the atmosphere 10Be is produced in the atmosphere by nuclear interactions with oxygen and nitrogen

(Peters, 1955, Goess and Phillips, 2001). The intensity of the cosmic ray flux depends on

galactic and solar sources, and modulation by the heliomagnetic and geomagnetic fields.

Both 10Be is produced by spallation reactions in the atmosphere, and then 10Be is well mixed

up (Ueikkila et al., 2009) and removed from the atmosphere by precipitation scavenging of

aerosol particles to land and sea. Eventually, these nuclides are deposited within ocean

sediment. The 10Be concentration at 10.7 km of stratosphere and at 19.2 km in the

tropospheric concentration are known to be 7 x 106 atoms/m3, and 1.3 x 107 atoms/m3,

respectively. The global average 10Be production rate is found to be (1.21±70) x 106

atoms/cm2/yr (Monaghan et al., 1985). Estimates of the 10Be production rate derived from

measurements on ice cores, lake sediments, and deep-sea sediments range from 0.35 x 106

atoms/cm2/yr to 1.89 x 106 atoms/cm2/yr. (Monaghan et al., 1985). Castagnolie et al., 2003

demonstrated reconstruction of the modulation parameter M from the open solar magnetic

flux proposed by Solanki et al., 2000, and experimental values calculated from the GCR

spectra measured with balloons and spacecraft are compared well with 10Be concentration

measured at the Dye3 ice core, assuming constant accumulation rate during the period of

1810-1997. The production rate of 10Be ranged from 0.015 to 0.025 atoms/cm2/s (Castagnolie

et al., 2003).

The precipitation onto the surface of the Earth and the deposition of 10Be in soils is

influenced by climate. In turn, the production of 10Be in the atmosphere is influenced by the

magnetic dipole field of the Earth to which it is inversely related. This relationship between

the production of 10Be and the geomagnetic field has been shown by the correlation between

the variations of 10Be and those of the measured paleo-inclination data of the dipole field in

sediments (Frank et al., 1997, Frank, 2000, Masarik et al., 2001, Laj et al., 2000), and the

concentrations of 10Be in marine sediments and the measured paleointensity (Carcaillet et

al., 2004, McHargue and Donahue, 2005).

The influence of climate on the deposition of 10Be, otherwise is problematic for

interpretations of the cosmic-ray flux, in itself is a worthy subject for study. For example,

variations in the deposition rates of 10Be and sediments affect the 10Be/9Be ratio due to the

uneven mixing of the two isotopes in the hydrological cycle. That, 10Be, produced largely in

the atmosphere, is transported to the surface of the earth by rain and dry precipitation to the

sea. In contrast, 9Be, derived from terrigenous materials, is transported to the sea largely by

rivers, and to a lesser extent by atmospheric deposition.

www.intechopen.com

Page 5: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

182

Location 10Be Source Reference

USA continent (1.38±0.36) ~(3.96 ± 0.35)

x 106 atoms/cm2/yr rain Monagahan et al., 1985

USA Hawaii 1.9 x 103 ~ 8.94 x 104

atoms/g rain Monagahan et al., 1985

Tropical region Avg. 1.53 x 104 atoms/g rain Monagahan et al., 1985

Illinois, USA 2 ~7 x 107 atoms/g soil Brown et al., 1989

Japan, Kikari Is (0.80 ~ 7.17) x 109

atoms/g soil Maejima et al., 2005

Japan, Kikari Is (2.0 ~ 3.5) x 106

atoms/cm/yr rain Maejima et al., 2005

New Zealand (2.1 ~ 2.9) x 104 atoms/g rain Graham et al., 2003

Korea, Masanri (0.67 ~ 1.47) x 108

atom/g soil Kim et al., 2011a

India (0.43~3.34) x 107 atoms/l rain Somayajulu et al., 1984

Global (1.21 ±0.70) x 106

atoms/cm2/yr rain Monagahan et al., 1985

Table 1. Production rate and concentration of 10Be in the rain and soil.

2.1.2 10Be in land surface Precipitation was collected for approximately one year during 1980 at seven localities in the continental U.S.A. (Monagahan et al., 1985). The 10Be flux ranged from (1.38±0.36) x 106 to (3.96±0.35) x 106 atoms/cm2/yr (Monagahan et al., 1985). In the case of Hawaii, 10Be concentration ranges from 1.9 x 103 to 8.94 x 104 atoms/g in rain water. The mean 10Be deposition rate in temperate latitude is determined to be 1.53 x 104 atoms/g in rain water (20% error). Monagahan et al., 1985 indicated that the concentration of 10Be in surface soils and river sediments varies between 107 and 109 10Be atoms/g soil with the modal concentration of 10Be lying between 4 x 108 and 6 x 108 atom/g. The relationship between annual rainfall and 10Be deposition rate is plotted to be linearly proportional to each other (Maejima et al., 2005). This study shows that 10Be fluxes (cm/day) for the two rain collection sites are relatively higher during a collection period of January 22 to April 22 than other collection period (Maejima et al., 2005). Seasonal variations for 7Be and 10Be concentration in Tokyo and Hachijo-Island during a period of 2002 to 2003 were similar to each other. The peak value for 7Be and 10Be concentration appeared in April and October, respectively. Especially, in April when stratosphere-troposphere exchange occurs, peak values for the atomic ratio 10Be/7Be appeared. Low 7Be and 10Be concentrations and the atomic ratio of 10Be/7Be appeared in summer, July to August. Because the composition of the aerosol of Tokyo was almost same to the nearby soil, it is considered that Tokyo was strongly influenced by re-suspended soil contamination. Yamagata et al., 2005 indicated that using Al concentration in the aerosols, the enrichment of 10Be concentration by re-suspended soil contamination was estimated to be about 30%. In the case of Southern Hemisphere, Graham et al., 2003 demonstrated 7Be and 10Be fluxes at

36 to 45S were determined to be (1.2~14) x 107 atoms/kg and (2.1~2.9) x 107 atoms/kg, respectively. These results are similar to those for rain sampled at mid-latitude sites across the USA from 1986 to 1994. The annual 7Be and 10Be flux rates are ~15 and ~27 x 109

www.intechopen.com

Page 6: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

183

atoms/m2, respectively, at the northern sites of Leigh and Gracefield, and are significantly lower at ~9 and ~19 x 109 atoms/m2, respectively, at the southern site of Denidin, because of the lower average rainfall there. Graham et al., 2003 indicated that 7Be/10Be in New Zealand ranged 0.47 to 0.61 and this is significantly lower than the ratio in USA (0.69~0.78). This is due to re-suspended dust to the primary atmospheric 10Be in the rain sample in New Zealand. Interestingly, the ratio of 7Be/10Be at three sites are 0.70 (Leigh), 0.65 (Gracefield) and 0.50 (Dunedin). These results suggest an overall reduction in the 7Be/10Be ratio from north to south, due to increasing residence time for Be isotopes in the atmosphere above New Zealand. The mean residence time for 7Be and 10Be in the atmosphere above New Zealand range from 77 to 109 days and are lower in the summer than the winter due to transfer of older stratospheric air to the tropopause in late spring-early summer (Graham et al., 2003). Maejiam et al., 2005 demonstrated that 10Be concentrations of six soil samples on the raised coral reef terraces of Kikari Island, southwest Japan ranged from 0.80 to 7.17 x 109 atoms/g. The annual deposition rate of 10Be from the atmosphere to Kikari Island from 2000 and 2002 ranged from 2.0 to 3.5 atoms/cm2/y. The minimum absolute age was calculated from the inventory of meteoric 10Be in the soil, and the annual deposition rates of 10Be are ranged from 8 to 136 kyr (Maejima et al., 2005). A 36 cm of soil depth profile from the Roberts Massif, Antarctica was studied to obtain the age of soil by Graham et al., 1997. The sampling site is located in the edge of the nearby East Antarctic Ice Sheet at an altitude of 2700 m. This site is considered to have been ice-free for an extremely long period of time, of the order of several million years. The results of Graham et al., 1997 determined its minimum soil age of 12 million years which is much older than other 40Ar/38Ar dating result of 8 million years for volcanic deposit, Scoria associated with soils on the tills laid down by the Meserve Glacier, Antarctica.

2.1.3 10Be in the ocean Using radiocarbon, the sedimentation rates during glacial periods and deglacial periods for the western Arctic Ocean were found to be 0.5 cm/kyr and 1-2 cm/kyr, respectively (Darby et al., 1997). A recent study shows that the concentration of 10Be in the authigenic fraction of the sediment normalized to the total sediment mass is indirectly correlated to the oxygen isotope curve (McHargue and Donahue, 2005). For example, a low 10Be/9Be ratio in sediments would imply that terrestrial source of 9Be has increased compared to the more oceanic 10Be. Correlation of 10Be with δ18O recorded in marine sediment from the Blake Outer Ridge (DSDP site 72) shows a climatic effect on the 10Be record in addition to cosmogenic effects. Age-corrected 10Be variability in the sediment cores studied in Aldahan et al., 1997 and the oxygen isotope stratigraphy with the climatic stages numbered from 1 to 10, is generated from Aldahan et al., 1997. 10Be from sediments of the Arctic Ocean covering the past 350 kyr shows well defined trends of Be isotopes coincident with interglacial/glacial climatic cycles and demonstrates that the sedimentation rates are higher during glacial periods and lower generally due to low sedimentation/accumulation rate during interglacial periods (Aldahan et al., 1997). The 10Be records of four sediment cores, taken along a transect from the Norwegian Sea via the Fram Strait to the Arctic Ocean, demonstrate that high 10Be concentration are related to interglacial stages and that sediment sequences with low 10Be concentration are related to glacial stages. This study confirms that the sharp contrast of high and low 10Be concentrations at climatic stage boundaries are an independent proxy for climatic and

www.intechopen.com

Page 7: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

184

sedimentary change, and can be applied for 10Be stratigraphic dating of sediment cores (Eisenhauer, 1994).

Fig. 1. Age corrected 10Be as a function of age (Aldahan et al., 1997).

Also, Carcaillet et al., 2004 produced high resolution authigenic 10Be/9Be records over the

last 300 kyr from sedimentary cores off the Portuguese coast. Comparison of 10Be/9Be and

benthic δ18O records from the two cores suggested that dipole moment lows may be

associated with the end of interglacial episodes, and have a quasi-period of 100 kyr

(Carcaillet et al., 2004). In a recent study, McHargue and Donahue, 2005 showed a strong

correlation between 10Be and oxygen isotope stages from the Blake Outer Ridge in the

Atlantic Ocean. This relationship between climate and 10Be deposition suggest that 10Be

could be used, in addition to, or as proxy for δ18O in the studies of the climatic influences on

marine sedimentation.

Other considerations are the carbonate flux in sediment which is strongly correlated to 10Be

flux, and carbonate-free sediments from which δ18O is difficult to obtain from foraminifera.

In addition, the two isotopes of beryllium, as stated above, are source dependent, thus the

relationship of 10Be to 9Be in the sediments is a function of the relative contributions from

atmospheric and terrestrial sources, and their mixing time in the sea.

Paleomagnetic intensity obtained from deep sea cores is well described in recent

publications (Valet, 2001, Guyodo et al., 2000, Guyodo and Richter, 1999). However, it was

found that climatic influence on 10Be deposition can be significant, obscuring those

variations from its production in the atmosphere, and thus must be addressed (Frank et al,

1997, Kok, 1999). Scavenging corrected 10Be records compared to calculated variation of the

global 10Be production based on paleomagnetic intensity records (Christl et al., 2003) (Figure

www.intechopen.com

Page 8: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

185

2) show the variation of 10Be flux in each location with general agreement of inversely

proposal to the paleomagentic intensity from Mazaud et al., 1994, Yamazaki and Iokyr et al.,

1994, and Guyodo and Valet, 1999.

Fig. 2. Scavenging corrected 10Be records compared to calculated variation of the global 10Be production based on paleomagnetic intensity records (Christl et al., 2003).

2.2 10Be chemistry Generally, to extract authigenic beryllium isotopes from sediments, the procedure of Bourles

et al., 1989 is used. About one gram of sediment is leached in a solution of 25% acetic acid

and hydroxlyamine-HCl to separate the “authigenic” fraction of the sediment from the

“terrigenous” fraction. Most samples had more than 1 g of dry sediment; however, in the

case of less than 1 g, two or three neighbouring samples were combined for the analysis.

When 10Be is normalized to the mass of the authigenic fraction, it should more accurately

reflect its concentration in ocean water than 10Be normalized to the total mass of the

sediment (McHargue and Donahue, 2005, McHargue et al., 2010). This fraction is mostly

composed of exchangeable ions, carbonates, and Fe-Mn hydroxides. Two aliquots of the

leachate are prepared, one for the elemental analysis with ICP-MS/ICP-AES, and one for the

preparation of AMS samples.

Figure 3 shows the flow chart of 10Be chemistry to extract authigenic beryllium from

sediment. This chemistry includes two steps of purification procedures using perchloric acid

and nitric/hydrochloric acid. These steps are important to extract authigenic brylllium

isotopes. Sometimes, this step is repeated to remove unwanted organic materials. When the

unwanted organic materials are not completely removed, the residue sample is often

difficult to dissolve in weak acidic solution for ICP analysis. This also causes a further

www.intechopen.com

Page 9: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

186

problem in the step of Be separation using Na-EDTA. The concentration level for Be is

mostly in ppb range; therefore, Be analysis was performed using ICP-MS. For AMS, the Be

fraction is precipitated as Be(OH)2 and combusted to BeO. 10Be/9Be ratios for chemical blank

are found to be less than ~ 1 x 10-14 with 2 mg of 9Be carrier. 9Be and other elements can be

measured by ICP-MS and ICP-AES.

Fig. 3. Description of authigenic Be isotope extraction method.

2.3 The climate signal of 10Be from nearby a continent The signal of 10Be from the East Sea in the Pacific Ocean and the Black Outer Ridge in the North Atlantic Ocean may give similar climatic influence because of its proximity to continents (Kim and Nam, 2010, McHargue et al., 2000). The depths of basins where sediment core collected were about 3,700 m and 3,818 m in the East Sea and Blake Outer Ridge, respectively. Because both cores were collected in the basin of the ocean, we might expect water circulation could be weaker. This could allow rather older waters can remain at the bottom of the basin. In this case, we may expect lower concentration of 10Be in sediment compared to samples collected from other open seas (Bourlès et al., 1989, Knudsen et al., 2008). Also, the influence from the continent would be similar in both regions. The terrestrial origin of 10Be over glacial/deglacial time period may similarly appear. As shown in Figure 4, three locations were examined with respect to 10Be concentration as a function of time and any related proxies for each site. Mostly, maximum 10Be concentrations in various marine sediment samples appear to be above 1 x 109 atoms/g sediment (Bourlès et al., 1989, Knudsen et al., 2008). Both the East Sea and Blake Outer Ridge, 10Be concentrations are reached at 8 x 108 atoms/g. This value is at least 30 percent lower than the most maximum value of 10Be in each marine sediment core. Also, when 9Be is investigated with 10Be, 9Be signal may be another indicator as a signal of sediment input from the land to the offshore. In the case of the study of the East Sea, the 9Be values also show similar trend to those of 10Be. his shows that both warmer periods of the Holocene and the Eemian,

www.intechopen.com

Page 10: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

187

Fig. 4. Locations of the coring sites of the East Sea, Black Outer Ridge, and Mendeleev Ridge in the western Arctic Ocean.

wetter and warmer climate influenced 9Be to be transported from the land to the ocean. 10Be is transported from the both land and atmosphere. The signal of 10Be/9Be especially stands for lack of either lack of 9Be transport or higher production rate of 10Be, possibly associated with paleomagnetic intensity. In Figure 5, A, B, and C are associated with relatively higher 10Be/9Be compared to neighbouring 10Be/9Be values. A could be partially due to lowered value of 9Be; B and C could be due to production rate of 10Be. This study shows high production rate of Be at 15.5 and near 120 kyr. Also, lower 10Be production rate is shown at 130.6 kyr during MIS 6 (Figure 5) (Kim and Nam, 2010). These three points can be identified easily with 10Be/9Be rations. In the Figure 5, the regions associated with climatic influence are clearly shown as the 10Be/9B ratios to be within the value between 2 and 3. This observation could be useful in future analysis. Based on Wagner et al., 2000, lower paleomagnetic intensities are associated with the ages at 1.5, 2.5, 4.0, and 6.5 kyr (Christl et al., 2003). Therefore, B could be likely involved in higher production rate of 10Be at 1.5 kyr (Kim and Nam, 2010) (Figure 5). Figure 6 shows the 10Be concentration and M/Mo as determined from measured NRM/ARM of core CH88-10P with respect to depth and time. This figure shows that 10Be concentration is inversely proportional to the relative paleomagnetic intensity. The production rate of 10Be occurred at about 40 and 65 kyr. The peak values of 10Be/9Be reached at maximum at about 40 kyr. This time period is named as Laschamp paleomagnetic excursion where the expected 10Be reaches at a maximum value. These paleomagnetic excursions are well compared with GRIP records. A recent investigation on 10Be and 9Be from the Mendeleev ridge in the Arctic Ocean shows that 10Be record at 75 kyr reveals production rate decrease evidently for at least 35 kyr of duration (Kim et al., 2011b). At this time the paleomagnetic intensity is found to be at maximum (Figure 2) (Christl et al., 2003; Flank et al., 1997). Interestingly, the values of magnetic susceptibility (Guyodo and Valet, 1996) obtained from a lake (Lac du Bouchet, France) are high as well as δ18O. Also, 9Be is relatively high which stands for a warm climate. The results of this study confirm that 10Be reveals predominantly paleomagnetic features over the δ18O at the extreme point of paleomagnetic intensity. This situation brings us to have precaution in a misuse of 10Be as a climatic tracer. This study confirms the fact that the 10Be record for climatic tracer, comparison with 9Be is essential. When both

www.intechopen.com

Page 11: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

188

AB

C

beryllium isotopes behaves similarly, the pattern of Be can be used to determine whether the record of Beryllium isotopes is associated with colder or warmer climate based on their consistent concentration trend. The total authigenic 10Be and 9Be (9Be>>10Be) can be referred as 9Be because of their amount ratio in terrestrial environment. The 9Be can be used as another climatic indicator like Sr, Ca, opal, TOC. The study at The Mendeleev Ridge confirms that 9Be generally has a positive correlation with opal, TOC, δ13Corg and negative correlation with CaCO3 (Nam unpublished) (Figure 7). General trend of 9Be clearly show the anti-correlation between 9Be and Ca or Sr (Boulrès et al., 1989, Kim et al., 2011b). Therefore, we can conclude that 10Be has a positive correlation with δ18O which gives 10Be to be used as a climate indicator, however, this is only true when 9Be reveals similar climatic pattern with 10Be. Both 10Be and 9Be show lower concentration at a cold/dry climate and higher concentration at a warm/wet climate period (Kim and Nam, 2010).

Fig. 5. Authigenic beryllium isotope records from the East Sea, Korea (Kim and Nam, 2010).

www.intechopen.com

Page 12: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

189

Fig. 6. The 10Be concentration and M/Mo as determined from measured NRM/ARM (Schwartz et al., 1998) of core CH88-10P versus depth and time (McHargue et al., 2000).

2.4 Current problem and future research A number of investigations show that there has been positive correlation between oxygen isotope and 10Be concentration (Aldahan et al., 1997). Also, a positive correlation between oxygen isotopes and paleomagnetic intensity and also magnetic susceptibility is investigated (Carcaillet et al., 2004). During the Holocene, paleomagnetic intensity was gradually increased since the time of Laschamp excursion. This confirmed that production rate of 10Be at present is the lowest value since Laschamp excursion. However, the 10Be values recent years are higher than the 10Be concentration and the trend of 10Be is similar to that of δ18O value. This implies that 10Be is closely related to climatic and temperature variation. Because of this contradictory fact, confining the cause of climate change using nuclides which sun’s activity related became important. Although there have been a number of investigation on climate study using above parameters, obscurity in finding the cause of climate change is still remain. The relationship among production rate of 10Be, paleomagenetic intensity, and Sun-climate connection was studied (Sharma, 2002). This study estimated changes in 10Be production rate and the geomagnetic field intensity, variations in solar activity were calculated for the last 200 kyr., and confirms that the production of 10Be in the Earth’s atmosphere depends on the galactic cosmic ray influx that is affected by the solar surface magnetic activity and the geomagnetic dipole strength. However, large variations in the solar activity are evident. The marine δ18O record and solar modulation are strongly correlated at the 100 kyr timescale. This proposes that variation in solar activity control the 100 kyr glacial-interglacial cycles. Sharma, 2002 suggested that the 10Be production rate variations may have been under-estimated during the interval between 115 kyr and 125 kyr, and may have biased the results (Sharma, 2002).

www.intechopen.com

Page 13: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

190

cold cold cold coldcold

Fig. 7. Multi-proxy record from the core (PS72/396-3) from Mendeleev Ridge, the Arctic Ocean (Kim et al., 2011b).

Usoskin et al., 2004 indicated that the reconstructed sunspot record exhibits a prominent period of about 600 years, in agreement with earlier observations based on cosmogenic isotopes. Also, there is evidence for the century scale Gleissberg cycle and a number of shorter quasi-periodicities whose periods seem to fluctuate on millennium time scale. This invalidates the earlier extrapolation of multi-harmonic representation of sunspot activity over extended time intervals and the present high level of sunspot activity is unprecedented on the millennium time scale (Usoskin et al., 2004). Accepting solar forcing of Holocene and galacial climatic shift implies that the climate system is far more sensitive to small variation in solar activity than generally believed. In order to fully understand how sensitive climate really is for variations in solar activity, we need to look for additional evidence and to quantify such evidence, both in paleorecords and in observations of present climate with models to estimate climate change in the future (Geel et al., 1999).

3. Conclusions

As a climate indicator, 10Be has been frequently investigated because of its property associated with rainfall, dust fallout and its production mechanism in the atmosphere by cosmic-rays. Similar patterns of 10Be and δ18O, magnetic susceptibility records show climatic influence, however, 10Be is incorporated with the production rate which is inversely proportional to the paleomagenetic intensity. The cyclic orbital forcing effect toward 10Be, δ18O, and paleomagenetic intensity are connected, 10Be signal is clearly mixed with climatic component and earth’s paleo magnetic strength. Scrutinizing authigenic 10Be with 9Be, a region either climatic or production related zone can be evidently identified by looking at the 10Be/9Be ratios. Investigation of 9Be is another useful tracer to examine climatic influence

www.intechopen.com

Page 14: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

191

of marine environments with other multi-proxies which have positive or anti-correlated with 9Be. Marine environments like the East Sea of Korea, Blake Outer Ridge, and Mendeleev Ridge are associated with significant terrigeous input during deglacial periods. Examining both beryllium isotopes together with other multi-proxy stratigraphy will provide understanding the pattern of environmental change at various glacial/interglacial events much more evidently.

4. Acknowledgment

This study is partially supported by Korean-IODP at Korea Institute of Geoscience and Mineral Resources and also funded by K-Polar (PP11070) at Korea Polar Research Institute.

5. References

Aldahan, A.; Ning, S.; Possnert, G.; Backman, J. & Bostrom, K. (1997) 10Be records from sediments of the Arctic Ocean covering the past 350 kyr. Marine Geology 144, 147-162.

Brown, L.; Stensland, G.; Klein, J., Middleton, R. (1989) Atmospheric deposition of 7Be and 10Be, Geochimica et Cosmochimica Acta 53, 135-142.

Bourlès, D.; Raisbeck, G. M. & Yiou, F. (1989) 10Be and 9Be in marine sediments and their potential for dating, Geochimica et Cosmochimica Acta 53, 443-452.

Carcaillet, J.; Bourlès, D.; Thouveny, N. & Arnold, M. (2004) A high resolution authigenic 10Be/9Be record of geomagnetic moment variation over the last 300 kyr from sedimentary cores of the Portuguese margin, Earth and Planetary Science Letters 219, 397-412.

Castagnoli, G. C.; Cane, D.; Taricco, C. & Bhandari, N. (2003) GCR flux decline during the last three centries : Extra terrestrial and terrestrial evidences, 28th Int. Cosmic Ray Conference, 4045-4048.

Champion, D. E. (1980) Holocene geomagnetic secular variation in the western United States: implications for the global geomagnetic field. U.S. Geological Survey Open-file Report, 80-824 , 1-314.

Christl, M.; Strobl, C. & Mangini, A. (2003) Beryllium-10 in deep-sea sediments; a racer for the Earth’s magnetic field intensity during the last 200,000 years, Quaternary Science Reviews 22, 725-739.

Darby, D. A.; Bischof, J. F. & Jones, G. A. (1997) Radiocarbon chronology of depositional regimes in the western Arctic Ocean, Deep-Sea Research II 44, 1745-1757.

Desilets, D.; Zreda, M. & Ferre,´ T. (2007) Scientist water equivalent measured with cosmic rays at 2006 AGU Fall Meeting, EOS Transactions AGU, 88(48), 521, doi:10.1029/2007EO480001.

Dunai, T. J. (2000) Scaling factors for production rates of in situ produced cosmogenic nuclides: a critical reevaluation, Earth and Planetary Science Letters 176, 157-169.

Eisenhauer, A. (1994) 10Be records of sediment cores from high northern latitudes: Implications for environmental and climatic changes, Earth and Planetary Science Letters 124, 171-184.

Frank, M.; Shwarz, B.; Baumann, S.; Kubik, P. W.; Suter, M. & Mangini, A. (1997) A 200 kyr record of cosmogenic radionuclide production rate and geomagnetic field intensity

www.intechopen.com

Page 15: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

192

from 10Be in globally stacked deep-sea sediments, Earth and Planetary Science Letters 149, 121-129.

Frank, M. (2000) Comparison of cosmogenic radionuclide production and geomagnetic field intensity over the last 2000,000 years, The Philosophical Transactions of the Royal Society, London A 358 , 1089-1107.

Geel., B. van; Raspopov, O. M.; Renssen, H.; Plicht, J. van der; Dergachev, V. A. & Meijer, H. A. J. (1999) The role of solar forcing upon climate change, Quaternary Science Reviews 18, 331-338.

Goess, J. C. & Phillips, F. M. (2001) Terrestrial in situ cosmogenic nuclides: theory and application. Quaternary Science Reviews, 20, 1475-1560.

Graham, I. J.; Barry, B. J.; Hemmingsen, I. D.; Hutchinson, E. F.; Pohl, P. K. & Zondervan, A. (2005) GNS science report, 2005/02, 43 p., Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand.

Graham, I. J.; Barry, B. J.; Ditchburn, R. G. & Zondervan, A. (2005) GNS science report 2005/03, 29 p.

Graham, I. J.; Barry, B. J.; Ditchburn, R. G.; Shea, M. A.; Smart, D. F. & Whitehead, N. E. (2005) GNS science report 2005/04, 32 p.

Graham, I. J.; Barry, B. J.; Ditchburn, R. G. & Whitehead, N. E. (2000) Nuclear Instruments and Methods B 172, 802-805.

Graham, I. J.; Ditchburn, R. G. & Whitehead, N. E. (1998) 10Be spikes in Plio-Pleistocene cyclothems, Wanganui Basin, New Zealand: identification of the local flooding surface (LFS), Sediment Geology, 122, 193-215.

Graham, I.; Ditchburn, R.; & Barry, B. (2003) Atmospheric deposition of 7Be and 10Be in New Zealand rain (1996-98), Geochimica et Cosmochimica Acta, 67 (3), 361-373.

Graham, I. J.; Ditchburn, R. G.; Sparks, R. J. & Whitehead, N. E. (1997) 10Be investigations of sediments, soil, and loess at GNS, Nuclear Instruments and Methods B123, 307-318.

Guyodo, Y. & Valet, J.-P. (1996) Relative variations in geomagnetic intensity from sedimentary rcords: the past 200,000 years, Earth and Planetary Science Letters 143, 23-36.

Guyodo, Y.; Gaillot, P. & Channell, J. E. T (2000) Wavelet analysis of relative geomagnetic paleointensity at ODP Site 983, Earth and Planetary Science Letters 184, 109-123.

Guyodo, Y. & Richter, C. (1999) Paleointensity record from Pleistocene sediments (1.4-0 Ma) off the California Margin, Journal of Geophysical Research, 104, B10, 22,953-22,964.

Guyodo, Y. & Valet, J.-P. (2010) Relative variations in geomagnetic intensity from sedimentary records:the past 200,000 years, Earth and Planet ary Science Letters, 143, 23-36.

Heikkilla, U.; Beer, J. & Feichter, J. (2009) Meridional transport and deposition of atmospheric 10Be, atmos. Chemical Physics, 9, 515-527.

Kim, K. J.; Zhou, L. P., Kim, J. H.; Kim, J. Y.; Park, Y. A. (2011a) Dating of aeolian sand deposits in Korea using OSL and Be-10, the 12th International Conference on Accelerator Mass Spectrometry, March 20-25, Wellington, New Zealand.

Kim, K. J.; Nam, S.-I.; Stein, R.; Mattiessen, J. (2011b) Glacial history and paleo-oceanographic changes of the western Arctic Ocean (Mendeleev Ridge) using beryllium isotopes , Arctic Science Summit Workshop, March 29-31, 2011, Seoul, Korea.

www.intechopen.com

Page 16: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Signals from

10Be Records of Marine Sediments Surrounded with Nearby a Continent

193

Kim, K. J. & Nam, S.-I. (2010) Climatic signals from the 10Be records of the Korean marine sediments, Nuclear Instruments and Methods, B 268, 1248-1252.

Kim, K. J.; Jull, A. J. T.; Kim, J.-H.; Matsuzaki, H.; Ohlendorf, C. & Zolitschka, B. (2010) Tracing Environmental Change of Potrok Aike, Argentina using Beryllium Isotopes, Geophysical Research Abstracts Vol. 12, EGU2010-3788-1, 2010 EGU General Assembly.

Kok, Y. S. (1999) Climatic influence in NRM and Be-derived geomagnetic paleointensity data, Earth and Planetary Science Letters, 166, 105-119.

Knudsen, M. F.; Henderson, G. M., Frank, M.; Niocaill, C. M. & Kubik, P. W. (2008) In-phase anomalies in Beryllium-10 production and palaeomagnetic field behaviour during the Iceland Basin geomagnetic excursion, Earth and Planetary Science Letters 265, 588-599.

Laj, C.; Kissel, C.; Mazaud, A.; Channell, J. E. T. & Beer, J. (2000) North Atlantic palaeointensity stack since 75 kyr (NAPIS-75) and the duration of the Laschamp event, Philosophical Transactions of Royal Society, London, A 358 , 1009-1025.

Laj, C. (1996) Alain Mazaud and jean-Claude Duplessy, Geomagnetic intensity and 14C abundance in the atmosphere and ocean during the past 50 kyr, Geophysical Res. Lett., vol 23, No. 16 , 2045-2048.

Lal, D. & Peters, B. (1967) Cosmic Ray Produced Radioactivity on the Earth, Handbuck der Physik, XLVI/2 , 551.

Lal, D. (1988) In situ-produced cosmogenic isotopes in terrestrial rocks, Annual Reviews of Earth and Planetary Science, 16, 355-388.

Lal, D. (1991) Cosmic ray labeling of erosion surfaces: in situ nuclide production rates and erosion models, Earth and Planetary Science Letters 104, 424-439.

Lifton, N. A.; Jull, A. J. T. & Quade, J. (2001) A new extraction technique and production rate estimate for in situ cosmogenic 14C in quartz, Geochimica et Cosmochimica Acta, 65, 1953-1969.

Horiuchi, K.; Kobayashi, K.; Oda, T.; Nakyrmura, T.; Fujimura, C.; Matsuzaki, H. & Shibata, Y. (2000) Climate-induced fluctuations of 10Be concentration in Lake Baikyrl sediments, Nuclear Instruments and Methods in Physics Research B172, 562-567.

Horiuchi, K.; Goldberg, E.L.; Kobayashi, K.; Oda, T.; Nakyrmura, T. & Kyrwai, T. (2001) Climate-induced variations of cosmogenic beryllium-10 in the sediments of Lake Baikyrl of the last 150 ky from AMS, SRXRF and NAA data, Nuclear Instruments and Methods in Physics Research. A470, 396-404

Mazaud, A.; Laj, C. & Bender, M. (1994) A geomagnetic chronology for Antarctic ice accumulation. Geophysical Research Letters 21, 337–340.

McHargue, L. & Donahue, D. J. (2005) Effects of climate and the cosmic-ray flux on the 10Be content of marine sediments, Earth and Planetary Science Letters, 232, 193-207.

McHargue, L. R.; Donahue, D.; Damon, P. E.; Sonett, C. P.; Biddulp, D. & Burr, G. (2000) Geomagnetic modulation of the late Pleistocene cosmic-ray flux as determined by 10Be from Blake Outer Ridge marine sediments, Nuclear Instruments and Methods in Physics Research B 172, 555-561.

McHargue, L.; Jull, A. J. T. & Cohen, A. (2010) Measurement of 10Be from Lake Malawi (Africa) drill core sediments and implications for geochronology. Palaeogeography, Palaeoclimatology, Palaeoecology, Doi. 10.1016/j.palaeo.2010.02.012.

www.intechopen.com

Page 17: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change – Geophysical Foundations and Ecological Effects

194

Masarik J. & Beer, J. (1999) Simulation of Particle fluxes and Cosmogenic Nuclide Production in the Earth’s Atmosphere. Journal of Geophysics Research, 104, 12099 (1999).

Masarik, J.; Frank, M.; Shafter, J. M. & Wieler, R. (2001) Correction of in situ cosmogenic nuclide production rates for geomagnetic field intensity variations during the past 800,000 years, Geochimica et Cosmochimica Acta 65 (17), 299-3003.

Maejima, Y.; Matsuzaki, H. & Higashi, T. (2005) Application of cosmogenic 10Be to dating soils on the raised coral reef terraces of Kikyri Island, southwest Japan, Geoderma, 126 389-399.

Monaghan, M. C.; Krishnaswami, S. & Turekian, K. K. (1985/86) The global-average production rate of 10Be, Earth and Planetary Science Letters, 76 (1985/86) 279-287.

O’Brien, K. A. (1979) Secular variations in the production of cosmogenic isotopes in the earth’s atmosphere. Journal, of Geophysical Research, 84, 423-31.

Ohno, M. & Hamano, Y., (1992) Geomagnetic poles over the past 10,000 years. Geophysical Reseach Letters, 19, 1715-18.

Peters, B. (1955) Radioactive beryllium in the atmosphere and on the earth, Proceedings of Indian Academy of Sciences, 41, 67-71.

Sharma, P. & Middleton, R. (1989) Radiogenic production of 10Be and 26Al in uranium and thorium ores: Implications for studying terrestrial samples containing low levels of 10Be and 26Al, Geochimica et Cosmochimica Acta, 53 , 709-716.

Sharma, P. & Somayajulu, B. L. K (1982) 10Be dating of large manganese nodules from world oceans, Earth and Planetary Science Letters, 59, 235-244.

Simpson, J. & Uretz, A. R. B. (1953) Cosmic-Ray Neutron Production in Elements as a Function of Latitude and Altitude, Physics Review, 90, No. 1 , 44-50.

Sharma, M. (2002) Variations in solar magnetic activity during the last 200,000 years: is there a Sun-climate connection? Earth and Planetary Science Letters 199, 459-472.

Somayajulu, B., L., K.; Sharma, P.; Beer, J.; Bonani, G.; Hofmann, H.-J.; Morezoni, e., Nessi, M., Suter, M. & Wolfli, W. (1984) 10Be annual fallout in rains in India, Nuclear Instruments and methods in Physics Research B5, 398-403.

Stone, J. O. (2000) Air pressure and cosmogenic isotope production. Journal of Geophysics Research, 105, 23,753-23,759.

Strack, E.; Heisinger, B. B.; Dockhom, B.; Hartmann, F. J.; Korshinek, G. & Noler, E. (1994) Determination of erosion rates with cosmogenic 26Al, Nuclear Instruments and Methods, B 92, 317-320.

Usoskin, I. G.; Mursular, K.; Solanki, S.; Schussler, M. & Alanko, K. (2004) Reconstruction of solar activity for the last millennium using 10Be data, Astronomy and Astrophysics, 413, 745-751.

Valet, J.-P. (2001) Time Variations in Geomagnetic Intensity, Reviews of Geophysics, 41/1, 4-44.

Yamagata, T.; Saito, T.; Nagai, H. & Matsuzaki, H. (2005) Seasonal variation for 7Be and 10Be concentrations in the atmosphere at Tokyo and Hachijo-Island during the period of 2002 and 2003, The 10th International Conference on Accelerator Mass Spectrometery, Sept. 5-10, Berkeley, CA. USA.

Yamazaki, T. & Iokyr, N. (1994) Long-term secular variation of the geomagnetic field during the last 200 kyr recorded in sediment cores from the western equatorial Pacific. Earth and Planetary Science Letters, 128: 527–544.

www.intechopen.com

Page 18: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

Climate Change - Geophysical Foundations and Ecological Effects

Edited by Dr Juan Blanco

ISBN 978-953-307-419-1

Hard cover, 520 pages

Publisher InTech

Published online 12, September, 2011

Published in print edition September, 2011

InTech Europe

University Campus STeP Ri

Slavka Krautzeka 83/A

51000 Rijeka, Croatia

Phone: +385 (51) 770 447

Fax: +385 (51) 686 166

www.intechopen.com

InTech China

Unit 405, Office Block, Hotel Equatorial Shanghai

No.65, Yan An Road (West), Shanghai, 200040, China

Phone: +86-21-62489820

Fax: +86-21-62489821

This book offers an interdisciplinary view of the biophysical issues related to climate change. Climate change is

a phenomenon by which the long-term averages of weather events (i.e. temperature, precipitation, wind

speed, etc.) that define the climate of a region are not constant but change over time. There have been a

series of past periods of climatic change, registered in historical or paleoecological records. In the first section

of this book, a series of state-of-the-art research projects explore the biophysical causes for climate change

and the techniques currently being used and developed for its detection in several regions of the world. The

second section of the book explores the effects that have been reported already on the flora and fauna in

different ecosystems around the globe. Among them, the ecosystems and landscapes in arctic and alpine

regions are expected to be among the most affected by the change in climate, as they will suffer the more

intense changes. The final section of this book explores in detail those issues.

How to reference

In order to correctly reference this scholarly work, feel free to copy and paste the following:

Kyeong Ja Kim and Seung-Il Nam (2011). Climate Signals from 10Be Records of Marine Sediments

Surrounded with Nearby a Continent, Climate Change - Geophysical Foundations and Ecological Effects, Dr

Juan Blanco (Ed.), ISBN: 978-953-307-419-1, InTech, Available from:

http://www.intechopen.com/books/climate-change-geophysical-foundations-and-ecological-effects/climate-

signals-from-10be-records-of-marine-sediments-surrounded-with-nearby-a-continent

Page 19: 4,800 122,000 135M · 2020. 5. 15. · case, the correction for geomagnetic reading may not be required, but the correction of production related to secular variation of geomagnetic

© 2011 The Author(s). Licensee IntechOpen. This chapter is distributed

under the terms of the Creative Commons Attribution-NonCommercial-

ShareAlike-3.0 License, which permits use, distribution and reproduction for

non-commercial purposes, provided the original is properly cited and

derivative works building on this content are distributed under the same

license.